GitLab CVE-2026-85706: One HTTP Request, No Authentication, Full File Read – Exploited Within 24 Hours

An issue has been discovered in GitLab CE/EE affecting only version 16.0.0. An unauthenticated malicious user can use a path traversal vulnerability to read arbitrary files on the server when an attachment exists in a public project nested within at least five groups.

CVE-2026-85706 is a path traversal flaw (CWE-35) in GitLab Community Edition and Enterprise Edition in which the repository commits API does not properly confine file paths and does not enforce authentication, allowing an unauthenticated attacker to read arbitrary files from the GitLab server. It is triggered by sending a crafted unauthenticated request to the commits API that supplies traversal sequences moving outside the intended repository path. An attacker gains the ability to read arbitrary files on the host, which can expose configuration files, certificates, and stored credentials or keys; related reporting on the recent GitLab patch wave also notes credential theft and code execution flaws, though this CVE itself is the file-read issue. All self-managed GitLab CE and EE deployments are in scope, and CISA did not publish specific affected version ranges in this data. The flaw was added to CISA's KEV catalog on 2026-09-11 and is being actively probed and exploited in the wild within a day of disclosure, with three public proof-of-concept repositories available; ransomware use is not yet confirmed.

Do: Upgrade GitLab CE/EE to the patched release identified in GitLab's security advisory (no specific fixed version number is provided in this data), prioritizing internet-facing instances in line with CISA BOD 26-04; if patching is not immediately possible, restrict exposure and review access logs for unauthenticated requests to the commits API containing path traversal sequences. Because arbitrary file read can expose server-side secrets, inventory and rotate credentials, tokens, and keys stored on or reachable by affected GitLab hosts.

GitLab EE contains a critical (CVSS 9.9) deserialization flaw (CWE-502) in which an authenticated user with Duo Chat access can pass a specially crafted GraphQL subscription argument that bypasses serialization and performs a server object lookup. Via this bypass, the attacker can obtain Advanced Search instance configurations and the sensitive credentials they contain. Because the attack requires only a low-privileged account with Duo Chat access over the network, with no user interaction, any EE deployment where Duo Chat is enabled is potentially exposed, including both self-managed instances and GitLab.com. Affected versions are EE 18.3 and later before 19.1.8, 19.2 before 19.2.6, and 19.3 before 19.3.2. No public proof-of-concept or CISA KEV listing exists for this CVE as of now, though related GitLab flaws disclosed in the same cycle are reportedly drawing internet-wide probing.

Do: Upgrade GitLab EE to 19.3.2, 19.2.6, or 19.1.8 depending on the version track in use. Until patched, restrict Duo Chat access to trusted users or disable it where feasible, and audit logs for unusual GraphQL subscription activity by authenticated Duo Chat users. After upgrading, rotate Advanced Search (Elasticsearch/OpenSearch) credentials and review search cluster configurations for signs of access.